As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems can include multiple electronic devices that communicate information. Such systems can include physical features that connect to any electronic device having a particular configuration. For example, in a server computer system, circuit boards bearing electronic components (sometimes called expansion cards) that communicate using the PCI local bus can be mounted to expansion connectors in a slot provided for that purpose. Such circuit boards can even connect to further devices. For example, a RAID expansion card can be mounted in a PCI expansion slot and further connected to multiple hard drives. Other devices that communicate with the PCI local bus can be directly mounted on the motherboard. In addition, hard drives and other power-intensive devices can be coupled to the motherboard through a SCSI connection. SCSI is a standard for connection of computer peripherals allowing a number of such devices to be coupled together and to the information handling device using a daisy chain arrangement. The amount of power drawn by such a series of connectors depends upon the type of device mounted in the expansion connectors and the number of such devices mounted in the expansion connectors.
Most expansion cards and SCSI devices are designed to operate based on a power input at a particular voltage. A power supply that would provide the correct voltage to a lightly loaded group of expansion connectors or SCSI connection may not provide the correct voltage for a heavily loaded expansion bus or SCSI connector. Many conventional computer power supplies include a remote sense connection, including both a positive and negative input. In some systems, the remote sense connection is coupled around a variable load (such as a position where a user could install one or more powered devices such as expansion cards) present in the system so that the power supply can react to whether the load is light or heavy and supply a voltage that takes the feedback into account and corrects that remote voltage to a desired level. For example, the power supply can compensate for the voltage drop in the power circuit including cables, connectors and/or PCB layouts. As a result, the devices receive a power input closer to their optimum voltage level.
In some systems, the power circuit includes two or more variable loads. Attaching the remote sense voltage input around one of those loads does not provide any feedback to the power supply regarding the voltage level or other electrical characteristic at the one or more other variable loads. For example, if the remotely sensed load is a series of expansion slots that are empty of expansion cards and the additional load is a SCSI connector with a large number of daisy-chained SCSI devices, the power supply will not receive feedback provided by the heavily loaded SCSI connector. In some systems, the variable load positions are present in different, parallel power circuits. In some cases, it is very important that devices receive the voltage at which they were designed to operate. Some devices operating at inappropriate voltages can have shorter usable life, drain more power, create more heat, and/or malfunction. The overall reliability of a system can be impacted if a critical device, for example a hard drive, malfunctions because it does not receive power in accordance with its specified electrical requirements.